A polycarbonate resin is widely utilized as an engineering plastic in a variety of fields, such as a field of office automation appliances and electric or electronic appliances and a field of automobiles, because of its excellent mechanical strengths (particularly impact resistance), electric characteristics and transparency. In recent years, utilization of liquid crystal displays (LCDs) has been expanded to note type personal computers, monitors and televisions. With such an expansion, an improvement of image quality is progressed. Thus, a backlight unit which is an illuminator for LCDs is required to have a higher brightness.
On the other hand, as typical in size reduction of note type personal computers, a thickness reduction of backlights is simultaneously being made. Thus, housings, flames and reflecting plates of those articles are required to have a high reflectance and to ensure a sufficient light shielding property even when they have a thin thickness.
However, as the thickness of molded articles decreases, the light shielding effect is reduced and, therefore, light more easily permeates therethrough. For example, the thickness of a frame of recent note type personal computers has been reduced to 0.5 mm in minimum. In order to prevent lack of hiding, it is thus necessary to take a special measure such as application of a black light-shielding tape to a necessary portion or, in another case, use of a white molded article in combination with a black molded article. Such measures result in complicated fabrication steps, increase of costs and hindrance to free design.
For example, a proposal has been made to incorporate titanium oxide in a composition for a housing of an illuminating device, which also functions as a reflector for reflecting a light incident from a light source disposed in the illuminating device, for the purpose of improving its light shielding property and of ensuring a sufficiency light shielding effect so long as the thickness thereof is about 1 mm or more (Patent Document 1). When the thickness is further reduced, however, a larger amount of titanium oxide must be used in order to obtain a higher light shielding effect. In this case, an increase of coloration or occurrence of silvering (silver stripes) a polycarbonate is unavoidable during the molding work due to reactive groups on surfaces of titanium oxide, even when a stabilizer is added.
A technique in which a laminate film having a light shielding layer is produced by coextrusion (Patent Document 2) and a technique in which a black film is laminated on a rear side of a white reflecting film (Patent Document 3) are also proposed. Such techniques have defects that lead to complicated works and an increase in number of parts.
A spacer for an electro-optical panel which contains a manganese oxide-based black pigment for the purpose of absorbing light is also proposed (Patent Document 4). In this case, since light absorption inevitably accompanies a decrease of light reflection, an illuminator having a molded article in which such a black pigment is used has a defect that leads to a reduction of the luminance thereof.    Patent Document 1: Japanese Patent Application Laid-Open No. H09(1997)-330048    Patent Document 2: Japanese Patent Application Laid-Open No. 2003-305811    Patent Document 3: Japanese Patent Application Laid-Open No. 2004-053759    Patent Document 4: Japanese Patent Application Laid-Open No. 2004-046205